Womail Waterproof 4x18650 Battery Storage Case Box Holder For Bike LED Light Black Material: Plastic and metal. The case can hold 4 x 18650 batteries (battery is not included) Size:9cm x 4.5cm x 4.5cm. Cable length: 55cm Can be placed in four 18650 batteries to power bicycle lights. Supports rain riding, can not be used for diving.